The annual revenue of Amazon.com rose from approximately $10.7 billion in 2006 to $34.2 billion in 2010.(a)Use this information to find both a linear model and an exponential model for Amazon.com's annual revenue I (in billions of dollars) as a function of time t in years since 2000. (Round all coefficients to three significant digits.)

linear model	I(t) =
exponential model	I(t) =

Which of these models would you judge to be more appropriate to the data shown below?

t (Year since 2000)	6	7	8	9	10
I ($ billions)	10.7	14.8	19.2	24.5	34.2

The ---Select--- linear model exponential model is more appropriate.(b)Use the better of the two models from part (a) to predict the 2007 figure and compare it with the actual figure above. (Round your answer to one decimal place.)The model yields an estimate of $ billion, which is not too far from the actual figure.